Does anyone see these Orphaned blocks as an attack by some of these Chinese Pools (specifically Antminer)?

More likely it's just Slush's pool backend not updating to other blocks on the network fast enough (or being really slow in releasing its own blocks). He's the only one having such absurd orphan rates, the problem is on his end.

Does anyone see these Orphaned blocks as an attack by some of these Chinese Pools (specifically Antminer)?

More likely it's just Slush's pool backend not updating to other blocks on the network fast enough (or being really slow in releasing its own blocks). He's the only one having such absurd orphan rates, the problem is on his end.

Presumably everything has slowed down due to the extra load of having so much hashrate on his pool. Since slush's pool code is python, it's likely just the slowdown of python not scaling to the greater number of clients it's seeing. He either needs more mining nodes or better software.

From memory, slush's pool used to prioritise which clients got block updates first - since it takes time to send updates to all the miners, he prioritised the biggest miners first so all the small miners used to get the block change later. Perhaps even that workaround is no longer enough.